Ipomoea batatas plant named ‘Fukumurasaki’

ABSTRACT

‘Fukumurasaki’ is a new variety of sweet potato plant bred by crossbreeding variety ‘Kyukei255’ and ‘Purple Sweet Lord’. The plant may be used, e.g., for cultivation of root tubers for consumption. The steamed flesh of ‘Fukumurasaki’ has a purple color, high sugar content, medium to viscous flesh quality, and excellent taste.

Plant name and variety denomination:

Latin name of the genus and species of the plant claimed: Ipomoea batatas. The claimed plant is a hybridization of different varieties of Ipomoea batatas.

Common names of the claimed plant's species: sweet potato.

Variety denomination: ‘Fukumurasaki’.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Japanese Patent Application No. 33033 filed Apr. 16, 2018, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND

Ipomoea batatas, commonly called sweet potato or sweet potato vine, is a dicotyledonous plant that belongs to the bindweed or morning glory family, Convolvulaceae. It is an herbaceous perennial that is cultivated for its edible root tubers. Ipomoea batatas is native to tropical regions of the Americas.

BRIEF SUMMARY

‘Fukumurasaki’ is a new variety of Ipomoea batatas bred by crossbreeding variety ‘Kyukei255’ as the female parent and ‘Purple Sweet Lord’ as the male parent. The plant may be used, e.g., for cultivation of root tubers for consumption. Neither ‘Kyukei255’ nor ‘Purple Sweet Lord’ are patented.

‘Fukumurasaki’ is a purple-colored lineage containing anthocyanins in its storage root. Although the yield of the good quality potatoes is inferior to that of ‘Kokei No. 14’ and ‘Purple Sweet Lord’, the steamed flesh of ‘Fukumurasaki’ has high sugar content, medium to viscous flesh quality, and excellent taste.

The flesh quality of the ‘Purple Sweet Lord’ is powdery and the sweetness is insufficient compared to the yellow flesh sweet potato. ‘Fukumurasaki’ has a lower yield of good quality potatoes than ‘Kokei No. 14’ and ‘Purple Sweet Lord,’ but has a medium to viscous flesh quality, and taste of the steamed flesh is medium to excellent. Because of the moderate resistance of ‘Fukumurasaki’ to sweet potato nematodes Meloidogyne incognita, cultivation in nematodes-rich areas should be avoided or controlled with pesticide or other measures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a photograph of ‘Fukumurasaki’ (left) leaves 3 months after planting compared to ‘Kokei No. 14’ (right).

FIG. 1B is a photograph of ‘Fukumurasaki’ (left) leaves 3 months after planting compared to ‘Purple Sweet Lord’ (right).

FIG. 2A is a photograph of ‘Fukumurasaki’ (left) root tuber and cross-section 5 months after planting compared to ‘Kokei No. 14’ (right).

FIG. 2B is a photograph of ‘Fukumurasaki’ (left) root tuber and cross-section 5 months after planting compared to ‘Purple Sweet Lord’ (right).

FIG. 3 is a photograph of the cultivation zone of ‘Fukumurasaki’ 3 months after planting.

FIG. 4 is a photograph of the whole plant body of Fukumurasaki’ (left) 3 months after planting compared to ‘Purple Sweet Lord’ (right).

DETAILED BOTANICAL DESCRIPTION OF THE PLANT

Variety: ‘Fukumurasaki’

Species of the plant claimed: Ipomoea batatas. The claimed plant is a hybridization of different varieties. The parental varieties are hybridization of different varieties.

Common names of the claimed plant's species include: sweet potato.

Characteristics of ‘Fukumurasaki’ provided herein were observed when the plant was cultivated in Okinawa and Satsuma, Japan. Descriptive terms used in Table 1 are consistent with the Japanese Examination Standard for Ipomoea batatas, available at website hinshu2.maff.gojp/info/sinsakijun/kijun/1347.pdf, the entire contents of which are incorporated herein by reference.

Properties and characteristics of ‘Fukumurasaki’, compared to the most similar varieties, are described in Table 1. For designated colors, the recognized color dictionary or color chart used is the Fifth Edition (2007) of “The Royal Horticulture Society Color Chart (R.H.S.).”

TABLE 1 Properties and characteristics of ‘Fukumurasaki’ Class Values of Class values Remarks most Char- of candidate (Meas- similar varieties acter- variety urement ‘Purple istic Charac- ‘Fuku- Value ‘Kokei Sweet No. teristics murasaki’ etc.) No. 14’ Lord’  1 Plant: growth semi-upright spreading spreading habit  2 Stem: length short 46.8 cm medium long of primary (106.2 cm) (157.4 cm) shoots and lateral branch  3 Stem: length short 2.6 cm medium long of (5.1 cm) (8.5 cm) internode and lateral branch  4 Stem: large 7.65 mm medium to medium diameter of large to large internode and (6.50 mm) (6.67 mm) lateral branch  5 Stem: weak absent or weak anthocyanin very weak coloration of internode and lateral branch  6 Stem: weak absent or weak anthocyanin very weak coloration of tip and lateral branch  7 Stem: medium absent or strong anthocyanin very weak coloration of node and lateral branch  8 Stem: dense sparse sparse pubescence of tip  9 Leaf blade: large 250.1 medium medium size cm² (160.9 to large cm²) (218.7 cm²) 10 Leaf blade: five lobes absent absent number of lobes 11 Only varieties — cordate triangular without leaf blade lobes: Leaf blade: shape 12 Only varieties moderate — — with leaf blade lobes: Leaf blade: depth of lobing 13 Excluding green 136A of Green Green ornamental RHS (136B (136B variety: Leaf of RHS) of RHS) blade: color on upper side (excluding anthocyanin coloration) 19 Excluding absent or absent or absent or ornamental very weak very weak very weak variety: Leaf blade: anthocyanin coloration on upper side 20 Leaf blade: absent or small large extent of very small anthocyanin coloration on abaxial veins on lower side 21 Leaf blade: very weak very weak weak intensity of anthocyanin coloration on abaxial veins on lower side 22 Leaf blade: absent or very absent or strong anthocyanin weak very weak coloration of nectary 23 Young leaf dark green N189A light green dark green blade: main of RHS (137A of (N189A color on upper RHS) of RHS) side 24 Young leaf medium N137A light green medium blade: main green of RHS (138A of green color on lower RHS) (N137A side of RHS) 25 Petiole: absent or absent or absent or anthocyanin very weak very weak very weak coloration 26 Petiole: length medium 24.4 cm medium medium to (22.4 cm) long (26.7 cm) 27 Corolla: — — — diameter 28 Corolla: color — — — 29 Storage root: ovate elliptic oblong shape 30 Storage root: moderately 4.6 moderately medium ratio elongated elongated (2.9) length/width (4.0) 31 Storage root: medium 3.8 medium medium number storage (3.1 (3.9 roots/ storage storage plant roots/ roots/ plant) plant) 32 Storage root: medium 142 g medium medium mean (146 g) to large weight (182 g) 33 Storage root: thick 0.072 medium medium thickness (0.055) (0.052) of cortex relative to overall diameter 34 Storage root: purple red 59C of red (182A purple red main color of RHS of RHS) (71B of skin RHS) 35 Storage root: absent absent absent secondary color of skin 36 Storage root: purple N77B of light beige Purple main color RHS (155D of (71C of flesh RHS) of RHS) 37 Storage root: medium medium medium intensity of main color of flesh 38 Storage root: white N155B — White secondary of RHS (N155B color of flesh of RHS) 39 Storage root: shallow medium medium depth of eyes 40 Storage root: purple N186B light beige light color of of HRS (2C of purple steamed flesh RHS) (79D of RHS) 41 Southern root- moderately moder- strong knot strong ately nematode weak (Pratylenchus caffeae) resistance N/A Original color Green 138B of Green Green of lateral RHS (138B (138B branch of RHS) of RHS) N/A Length of 15.9 cm 13.0 cm 15.5 cm Leaf N/A Width of Leaf 15.7 cm 12.3 cm 14.0 cm N/A Original color Green 138B of Green Green of petiole RHS (138B (138B of RHS) of RHS)

Cross-breeding was carried out in 2004 in Miyazaki prefucture, Japan. From 2005 onwards, selection and breeding were carried out in Japan. Based on the result of seedling individual selection test in 2005, a lineage was selected which showed excellent in appearance and root tuberization, and gave the lineage number of ‘Kyukei 04008-3’. Thereafter, they were used for the lineage selection preliminary test in 2006, the lineage selection test in 2007, and the productivity check preliminary test in 2008. As a result of examining various characteristics, we selected a lineage with excellent color of flesh and excellent characteristics of the steamed flesh, from ‘Kyukei 04008-3’, and gave the lineage number of ‘Kyukei 288’. And, since 2009, a productivity check test, a lineage adaptability test (Nagasaki, Ehime, etc.), a black rot (Ceratocystis fimbriata) resistance test (Nagasaki), and a damping-off resistance test (Tokushima) have been carried out, with the lineage number of ‘Kyukei 288’. Finally, ‘Fukumurasaki’ was selected by comprehensively examining the results of these tests.

Morphological Characteristic

The plant growth habit in a field is the “semi-upright” type, and length of primary shoots and the length of internode of the stem are shorter and the diameter of internode is slightly larger than the ‘Kokei No. 14’ and the ‘Purple Sweet Lord’.

The coloration of ‘Fukumurasaki’ internode is “weak” and the coloration of node is “weak to medium”, the color on upper side of young leaf is “dark green” (N189A of RHS) and the color on back side of young leaf is “green” (N137A of RHS), the leaf color is “green” (136A of RHS), the leaf size is “large”, the number of lobes in leaf blade is “5”, and the leaf shape according to the old reference is “double-incision”.

The extent of the coloration on abaxial veins on lower side of the leaf is “absent or very small”, the intensity of the coloration of the same is “very weak”, and the coloration of the nectary is “absent or very weak”. The arrangement of the leaves is alternate.

The strength of the storage root's neck and the position of the storage root (same as depth from the field surface to storage root) are “medium”, and the difficulty of digging (harvesting) the storage root (same as root tuber) is “medium”. The shape of storage root is “ovate” in the new standard and “long spindle” in the old standard.

Shape regularity of storage roots is “moderate”; size of storage roots is “medium”; size regularity of storage roots is “medium”, mean length of storage roots is 19.7 cm±3.0 cm and mean width of storage roots is 4.4 cm±0.4 cm; skin color of storage root is “purple red” (59C of RHS); flesh color is “purple” (N77B of RHS); depth of eye in storage root is “shallow”; skin roughness of storage root is “slightly coarse”; grooves and ridges of storage root are “absent”; dehiscence of storage root is “little”; appearance is “medium”.

At earlier harvest timing under cultivation with mulching sheet, the total weight of good quality storage roots of ‘Fukumurasaki’ is about 60% of that of ‘Kokei No. 14’. Under later-planting-timing cultivation without mulching sheet, the total weight of good quality storage roots is about 60% of that of ‘Kokei No. 14’. The mean weight of one good quality storage roots is lower than that of ‘Kokei No. 14’. The number of good quality storage roots per one plant is equivalent to that of ‘Kokei No. 14’. The percentage of dry matter content is about 5 points higher (at the earlier harvest timing), and about 7 points higher (under later-planting-timing cultivation) than those of ‘Kokei No. 14’. Table 2 below contains mean numerical values for characteristics of the good quality storage roots.

TABLE 2 ‘Purple Cultivation ‘Fuku- ‘Kokei Sweet method Characteristic murasaki’ No. 14’ Lord’ Standard Weight of the 201 kg/a 249 kg/a — cultivation good quality with black storage roots mulching Mean weight of 127 g 192 g 194 g sheet one good quality storage root No. of good  4.2  3.5  4.2 quality storage roots per plant Percentage of  37.2%  31.6% — dry matter content Cultivation Weight of the 104 kg/a 163 kg/a — with good quality transparent storage roots mulching Mean weight of  85 g 131 g — sheet at earlier one good quality harvest timing storage root No. of good  3.1  3.3 — quality storage roots per plant Percentage of  36.4%  31.5% — dry matter content Later-planting Weight of the 107 kg/a 173 kg/a — timing good quality cultivation storage roots without Mean weight of 106 g 154 g — mulching one good quality storage root No. of good  2.7  3.0 — quality storage roots per plant Percentage of  34.6%  27.6% — dry matter content Ecological Characteristics

The timing (early or late) of sprouting of ‘Fukumurasaki’ from storage root, the timing regularity of sprouting from different storage roots (almost simultaneous or not), the speed of sprout elongation, and the number of sprouts are “medium”, mean numerical value 8-10 sprouts, and the sprouting trait (same as sprouting habit) is “medium”.

On average, the total weight of the good quality storage roots is 19% lower than that of ‘Kokei No. 14’. The mean weight of one good quality storage roots is lower than that of ‘Kokei No. 14’ and ‘Purple Sweet Lord’. The number of good quality storage roots per one ‘Fukumurasaki’ plant is slightly larger than that of the ‘Kokei No. 14’ and equivalent to that of the ‘Purple Sweet Lord’. The percentage of dry matter content is about 5.6 points higher than that of ‘Kokei No. 14’.

The resistance of ‘Fukumurasaki’ to sweet potato nematodes (M. incognita) is “medium” and the resistance to Minami root-lesion nematodas (P. coffeae) is “moderately strong”. The resistance to black rot (Ceratocystis fimbriata) disease is “medium to strong”. The resistance to damping-off is “slightly weak to slightly strong”, and the resistance to stem rot (Fusarium oxysporum f, sp. batatas) is “strong”. Storability of storage root is “medium”.

Regarding temperature tolerance of ‘Fukumurasaki,’ the preferable temperature for growth is 16 degrees Celsius or higher. More preferably, the temperature for growth is 20-35 degrees Celsius. Temperatures under 9 degrees Celsius can sometimes cause low-temperature damage to the plant.

Quality Characteristics and Processability

In standard cultivation, the steamed flesh color of the ‘Fukumurasaki’ storage root is “purple” (N186B of RHS), fibers in steamed flesh is “medium”, and the quality of flesh is “medium”. The taste of steamed or roasted storage root is “somewhat superior” and Brix is higher than ‘Kokei No. 14’ and ‘Purple Sweet Lord’.

Other Characteristics

Brix of ‘Fukumurasaki’ steamed storage root is higher than ‘Kokei No. 14’ and ‘Purple Sweet Lord’ in both the cultivation with transparent mulching sheet at earlier harvest timing and the later-planting-timing cultivation without mulching. For standard cultivation with black mulching sheet, Brix numerical values are as follows. Brix for steamed storage root is 24.8% for ‘Fukumurasaki,’ 16.6% for ‘Kokei No. 14,’ and 13.4% for ‘Purple Sweet Lord.’ Brix for roasted storage root is 24.7% for ‘Fukumuraksi,’ 17.5% for ‘Kokei No. 14,’ and 14.7% for ‘Purple Sweet Lord.’ For cultivation with transparent mulching sheet at earlier harvest timing, Brix numerical values are as follows. Brix for steamed storage root is 19.6% for ‘Fukumurasaki,’ 16.3% for ‘Kokei No. 14,’ and 13.8% for ‘Purple Sweet Lord.’ For later-planting-timing cultivation without mulching, Brix numerical values are as follows. Brix for steamed storage root is 19.5% for ‘Fukumurasaki,’ 15.3% for ‘Kokei No. 14,’ and 16.2% for ‘Purple Sweet Lord.’

The taste of ‘Fukumurasaki’ steamed storage root is “medium” under the cultivation with transparent mulching sheet at earlier harvest timing, and “slightly higher” under the later-planting-timing cultivation without mulching.

In October, 2016, samples (storage roots) cultivated in the field in the city of Namegata were stored for about 70 days, and then each sample was roasted at 200° C. for 1 hour to prepare roasted samples (roasted sweet potatoes), and sensory evaluation by panelists was carried out. ‘Fukumurasaki’ was more viscous than ‘Purple Sweet Lord’ in terms of roasted flesh quality, superior in texture and sweetness, and ‘Fukumurasaki’ exceeded ‘Purple Sweet Lord’ in overall evaluation.

‘Fukumurasaki’ was grown in open culture. In Japan, planting occurs in the early part of May to the end part of May. In Japan harvesting time is the middle part of October to the end part of October.

It will be understood that the average size of the plant and storage root may vary with location, season, nutrition, irrigation, etc. 

What is claimed is:
 1. A new and distinct Ipomoea batatas plant named ‘Fukumurasaki’ as illustrated and described. 